Fuel oil composition



United States Patent FUEL OIL COMPOSITION Harry J. Andress, Jr., Pitman,N.J., assignor to Socony Mobil Oil Company, Inc., a corporation of NewYork No Drawing. Filed Oct. 24, 1956, Ser. No. 617,911

Claims. (Cl. 44-78) This invention has to do with improved fuel oilcompositions. More specifically it has to do with fuel oils which havebeen stabilized and which are particularly suitable for use asindustrial and domestic fuels.

The fuel oils improved in accordance with this invention are hydrocarbonfractions having initial boiling points of at least about 100 F. and endpoints not higher than about 750 F., and which boil substantiallycontinuously throughout their distillation ranges. Such fuel oils aregenerally known as distillate fuel oils. It is to be understood,however, that this term is not restricted to straightrun distillatefractions. Thus, as is well known to those skilled in the art, thedistillate fuel oils can be straightrun distillate fuel oils,catalytically or thermally cracked distillate fuel oils or mixtures ofstraight-run distillates, naphthas and the like, with cracked distillatestocks. Moreover, such fuel oils can be treated in accordance with wellknown commercial methods, such as, acid or caustic treatment, solventrefining, clay treatment, etc.

The distillate fuel oils are characterized by their relatively lowviscosities, pour points and the like. The principal property whichcharacterizes the contemplated bydrocarbon fractions, however, is thedistillation range. As mentioned hereinbefore, this range will liebetween about 100 F. and about 750 F. Obviously, the distillation rangeof each individual fuel oil will cover a narrower range falling,nevertheless, within the above-specified limits. Likewise, each fuel oilwill boil substantially, continuously throughout its distillation range.

The fuel oils particularly contemplated herein are Nos. 1, 2 and 3 fueloils used in domestic heating and as diesel fuel oils, particularlythose made up chiefly or entirely of cracked distillate stocks. Thedomestic heating oils generally conform to the specification set forthin ASTM Specifications D396-48T. The specifications for diesel fuels aredefined in ASTM Specifications D975-48T. contemplated herein also arefuels for jet combustion engines. Typical jet fuels are defined inMilitary Specification MIL-F-5624B.

As is well known, fuel oils of the above-defined character have atendency to deteriorate in storage and to form colored bodies and sludgetherein. This deterio-ration of the oil is highly undesirable in that itcauses serious effects on the characteristics of the oil, particularlyon the ignition and burning qualities thereof. It is also a contributoryfactor, along with the presence of other impurities in the oil, such asrust, dirt and moisture, in causing clogging of the equipment parts,such as screens, filters, nozzles, etc., as is explained hereinbelow. Animportant economical factor is also involved in the problem of oildeterioration in storage, viz., customer resistance. Thus, customersjudge the quality of an oil by its color and they oftentimes refuse topurchase highly colored oils. It will be appreciated, then, that sincefuel oils of necessity are generally subject to considerable periods ofstorage prior to use, the provision of a practical means for preventingthe deterioration of the fuel oil during Patented May 16, 1961 suchstorage would be a highly desirable and important contribution to theart.

Another and distinct problem that has plagued fuel oil manufacturers andusers is that referred to as screenclogging. This involves thedeposition of foreign sub stances, such as water droplets, rust and dirtparticles, as well as any sludge material formed by the deterioration ofthe oil, on the metallic surfaces of screens and filters of burners andengines in which the oil is utilized. Additives have been developed toimpart anti-clogging properties to fuel oils, functioning therein toinhibit the aforesaid deposition of foreign substances. The mechanism bywhich the clogging is prevented involves the adsorption of theanti-clogging agent or additive on the metal surfaces whereby thecontacting of these surfaces by the foreign substances and/or preformedsludge is prevented. In this way, deposition and buildup of thesematerials on the metal surfaces is avoided. It will be appreciated,therefore, that the problem of preventing screen-clogging by fuel oilsis entirely different from that of preventing the formation of sedimentand color therein as occurs in the oil during prolonged periods ofstorage. Thus, it will be appreciated that any fuel distribution systemwill contain small amounts of foreign substances, such as condensedmoisture and particles of rust and dirt, which become entrained in theoil, even though the oil has not been stored for any appreciable lengthof time. On the other hand, fuel oils which have been in storage forsubstantial periods of time Will also contain another kind of sediment,or sludge, which is produced by the gradual deterioration of the oil perse. This sediment, or sludge, is formed in the oil as the result ofchemical phenomena. Thus, during storage, oxidation of the variouscomponents of the oil, such as pyrrolic compounds, phenols andthiophenols present therein, takes place forming quinoid molecules whichcondense with one another and/ or with other active hydrogen. compoundsalso pres ent in the oil to produce highly colored bodies of increasingmolecular weight. When an oil has been in storage for any substantialperiod of time these compounds separate out as insoluble sludge.Additives have also been developed to inhibit the formation of sedimentor sludge in the oil due to oxidative deterioration of the oil instorage, as above described. Such additives act by inhibiting theinitial oxidation and the subsequent reactions which produce suchsludge.

It is apparent, then, that the problem of preventing screen-clogging byfuel oils is entirely different from the problem of preventing theformation of sediment and color therein as occurs in the oil duringprolonged periods of storage. As evidence of the difference betweenthese problems, additives which prevent screen-clogging have generallylittle or no effectiveness in preventing the formation of sediment andcolor. Correspondingly, other additives which effectively inhibitsediment and color formation generally have little or no anti-screenclogging properties.

It is the object of this invention to stabilize fuel oils.

It is a further object of the invention to provide fuel oils stabilizedagainst the formation of sediment therein.

Still another object of the invention is to provide a fuel oil free fromscreen-clogging tendencies.

An important object of the invention is to provide a fuel oil stabilizedagainst the formation of sediment and color and also free fromscreen-clogging tendencies.

A still further object of the invention is to provide a fuel oil havingexcellent anti-rust properties.

Additional objects of the invention will be apparent from the followingdescriptions:

It has now been found that the aforesaid objects are realized byincorporating in a fuel oil of the foregoing character, a small amountof a fuel-oil-soluble reaction product obtained by reacting an aldehydeand paraffinwax-substituted hydroxyaromatic compound, and furtherreacting the resulting product with an alkylene oxide. The products soobtained, most probably, contain one or more of the compoundsrepresented by the following general formula:

wherein R and R are the same or different paraffin wax groups; n and mthe same or different small whole numbers each being from 1 to 3; A isphenyl or naphthyl; p and q are the same or different small wholenumbers each being from 1 to 3; R" and R'" are the same or differentalkylene or hydroxy alkylene groups, each containing at least 2 carbonatoms and preferably 2 to 4 carbon atoms; r and s are the same ordifferent small whole numbers, each being at least 1 and preferably from1 to 20; and R"" is hydrogen, or an alkyl, cycloalkyl, aryl or heterogroup.

As indicated, one of the reactants is a paraflin-waxsubstituted phenolor naphthol, the aromatic nucleus of which is preferably otherwiseunsubstituted. The aromatic nucleus carries from 1 to 3 hydroxy groupsdirectly attached thereto, and from 1 to 3 paraffin wax groups. Suchcompounds are represented by the general Formula II:

wherein R, A, n, m, p and q are as defined above. Representative ofthese compounds are paraffin-wax-substituted phenols, resorcinols,hydroquinones, pyrogallols, and the correspondingparaflin-wax-substituted hydroxy naphthalenes. Particularly preferredherein are the paraffinwax-substituted phenols.

The aldehydes used in the reaction with the aforementioned phenols andnaphthols, can be aliphatic, cycloaliphatic, aromatic or heterocyclic.Representative of such aldehydes are formaldehyde (e.g.,paraformaldehyde), acetaldehyde, propionaldehyde, stearylaldehyde,benzaldehyde, tolualdehyde, salicylaldehyde, furfural, and thiophenealdehyde. Preferred herein is formaldehyde, in view of the particularlyadvantageous products obtained therewith.

Alkylene oxides, as indicated above, are used herein. These can beeither monooxides or polyoxides. Thus, they can contain one or more ofthe characterizing group Typical of such compounds are ethylene oxide,propylene oxide, butylene oxide, butane dioxide, bis-(2,3-epoxy propyl)ether otherwise referred to as diglycide ether, isoprene dioxide,hexadiene dioxides, limonene dioxide, etc. Particularly preferred hereinis ethylene oxide.

The products contemplated herein for use in fuel oils are prepared byreacting one molar proportion of a parafiin wax-substituted phenol ornaphthol with at least 1 molar proportion and preferably 1 to 2 molarproportions of an aldehyde, and thereafter reacting 1 molar proportionof the intermediate phenol-aldehyde product with at least one molarproportion and preferably 1 to 20 molar proportions of an alkyleneoxide. Temperatures at which the phenol and aldehyde are reacted arefrom about 50 C. to about 250 C., most advantageously within the rangeof 100 C. to 200 C. Similarly, temperatures used during reaction of theintermediate phenolaldehyde product and the alkylene oxide can be variedfrom about 20 C. to about 250 C., preferably from 100 C. to 200 C.Generally, atmospheric pressure 4 suflices in completing the reactions;however, superatmospheric pressures can also be employed.

Acid or basic catalysts are used in facilitating reaction of thealdehyde and the phenol or naphthol. Such catalysts are well know forthis reaction. Basic catalysts are used in reacting the alkylene oxidewith the aldehydephenol or aldehyde-napththol product. Typical of suchcatalysts are sodium, potassium, lithium, calcium and barium hydroxides,and preferably sodium hydroxide; amines such as pyridine; quaternaryammonium hydroxide.

It is to be understood that the products of this invention can also beprepared by an alternative but less advantageous procedure, whichinvolves reaction of the intermediate reaction products with ahalohydrin or an epichlorhydrin and an alkali, such as sodium hydroxide.

The products of this invention have been described as reaction productsrather than as specific chemical compounds since the structure of some,at least, is yet unknown. In particular, paratfin-wax-substitued phenolsand naphthols have not been fully identified, but it would appear thatthey contain predominant amounts of the following respective compounds:

wax O H and O H wax Therefore, when the paraflin-wax-substituted phenolsand naphthols are reacted with an aldehyde, such as formaldehyde, theresulting product cannot be defined as a single specific compound.Obviously, then, when the aldehyde product is reacted with an alkyleneoxide, such as ethylene oxide, the resulting product cannot be definedas a definite structure. It follows, however, that the resulting productmost probably contains a predominant amount of the following respectivecompounds:

and

wax

wax

The following specific examples are for the purpose of illustration. Itis to be understood, however, that this invention is not to be limitedby the particular additive and fuel oils, or to the operations andmanipulations described herein. Other reaction products and fuel oils ofthe above-described character are utilizable, as those skilled in theart will readily appreciate.

PREPARATION OF WAX-PHENOL (3-14) A parafiin wax melting at approximatelyF. and predominantly comprised of hydrocarbons, having at least 20 andan average of about 24 carbon atoms in their molecules, is melted andheated to about 200 F., after which chlorine is bubbled therethroughuntil the wax has absorbed about 14%, by weight, of chlorine. Asufficient quantity of this chlorinated wax to provide 3 atomicproportions of chlorine is then heated to a temperature varying fromjust above its melting point to not over 150 F. One mol of phenol (C H0H) is then mixed with the chlorowax. The mixture is then heated toabout 150 F. and a quantity of anhydrous aluminum chloride,corresponding to about 3% of the weight of the chlorowax in the mixture,is slowly added with active stirring. The rate of addition of thealuminum chloride should be sufficiently slow to avoid violent foamingand during the addition the temperature should be held at about 150 F.After the aluminum chloride has been added the temperature of themixture may be increased slowly over a period of from 15 to 25 minutesto a temperature of about 250 F. and then should be more slowlyincreased to about 350 F. To control the evolution of HCl gas, thetemperature of the mixture is preferably raised from 250 F. to 350 F. ata rate of approximately one degree per minute, the whole heatingoperation occupying approximately two hours from the time of adding thealuminum chloride. If the emission of HCl gas has not ceased when thefinal temperature is reached, the mixture may be held at 350 F. for ashort time to allow completion of the reaction. However, to avoidpossible cracking of the wax, the mixture should not be heatedappreciably above 350 F. nor should it be held at that temperature forany extended length of time.

It is important that all unreacted, or non-alkylated, phenol remainingin the reaction mixture, as well as aluminum chloride, be removed. Thiscan be conveniently effected by washing the product several times with amixture of water and an alcohol, such as butanol, preferably at elevatedtemperature, say 175 F. The product may then be treated with steam. Thislatter step will insure complete removal of the unreacted material andalso dry the product.

It will be understood that a wax-substituted phenol prepared accordingto the above procedure in which a quantity of chlorowax containing threeatomic proportions of chlorine and having a chlorine content of 14% isreacted with one mol of phenol, is designated as wax phenol (3-14).Similarly, wax-phenol (3-10) and wax-phenol (1-10) may also be preparedby the reaction of sufficient amounts of chlorinated wax, containingpercent by weight of chlorine, to provide 3 atomic proportions and 1atomic proportion of chlorine per mol of phenol, respectively, in thereaction and are useful in the invention. In general, the amount ofchlorowax, containing from about 10 to 18 percent by weight of chlorine,used in the reaction is sufficient to supply between 1 and 4 atomicproportions of chlorine per mol of phenol used.

Further details relative to the procedure for the preparation of waxphenols suitable for use herein may be had by reference to Patent No.2,191,499, issued February 27, 1940, to Orland M. Reiif.

Example I A mixture of wax-phenol (3-14) (400 parts by weight), diluentoil (400 parts by weight), sodium hydroxide (4 parts by weight) andparaformaldehyde (1 mol) parts by weight), was slowly heated to 200 C.Ethylene oxide gas was bubbled through the mixture so formed at 200 C.until the resulting reaction mixture increased 92 parts by weight. Thereaction product was then neutralized with concentrated hydrochloricacid and the sodium chloride formed thereby was removed by filtration.The productreferred to herein as Product I-is predominantly a methylenebis wax phenoxy triethoxy ethanol, one part of oil for one part ofproduct.

The diluent oil is a paraffinic oil having a Saybolt viscosity of 100seconds at 100 F.

The effectiveness of the additives of this invention in stabilizing atypical fuel oil against sediment formation therein, is shown byscreen-clogging test data. The amount of screen-clogging is determinedwith a Sunstrand V3 or S1 home fuel oil burner pump having aselfcontained, -mesh Monel metal screen. About 0.05 percent, by weight,of a naturally-formed fuel oil sludge, composed of fuel oil, water,dirt, rust, and organic sediment, is added to ten liters of the fuel oilunder test. This mixture is circulated by the pump through the screenfor six hours. Then the sludge deposited on the screen is washed offwith normal pentane, and filtered through a tared asbestos (GoochCrucible) filter. After it is dried, the material on the filter iswashed with a 50-50 (volume) acetone-methanol mixture. The total amountof organic sediment is determined by evaporating the n-pentane and theacetone-methanol filtrates, and weighing the residue. The Weight of thematerial on the filter is the amount of inorganic sediment deposited.The sum of the weights of the organic and the inorganic deposits, inmilligrams, gives the weight of sludge deposited, which weight iscompared with the weight of sludge deposited from the uninhibited(blank) fuel oil to determine the percent of screen-clogging. Theuninhibited fuel oil, after six hours on test, effects 100 percentscreenclogging. Thus, the comparison percentagewise between the weightof sludge deposited by the uninhibited fuel oil and the inhibited fueloil affords a measure of the percent of screen-clogging. The fuel oilused in the test is a blend comprising sixty percent (by weight) ofcatalytically cracked component and 40% of straightrun component, theblend having a boiling range from about 320 F. to about 640 F. The dataobtained from said tests are provided in Table I.

The results set out in Table I demonstrate that Product I, contemplatedherein, is an effective anti-screenclogging agent. The resultsdemonstrate also that waxphenol (3-14) is ineifective.

A demonstration of the sediment inhibiting character of the additivescontemplated herein is shown by results of F. storage tests. In thistest, a 500-milliliter sample of the fuel oil under test is placed in aconvected oven maintained at 110 F. for a period of twelve weeks. Then,the sample is removed from the oven and is cooled. The cool sample isfiltered through a tared asbestos filter (Gooch Crucible) to remove theinsoluble matter. The Weight of such matter, in milligrams, is reportedas the amount of sediment. In this test, a sample of the blank,uninhibited oil is run along with the fuel oil blend under test. The oilused is the same as that described above in connection with Table I. Theeffectiveness of a fuel oil composition containing an inhibitor isdetermined by comparing the test data therefor with the test data forthe uninhibited blank oil. Results of the storage tests are given inTable II.

The results given in Table H reveal that Product I is effective inmaterially reducing sediment formation.

The reaction products of this invention are used in fuel oilsinconcentrations varying between about 1 pound per thousand barrels ofoil, and about 200 pounds per thousand barrels of oil. Preferably, theconcentration will vary between about 10 and 100 pounds per thousandbarrels. In terms of weight percent, based upon the weight of the fueloil, the concentrations vary preferably between about 0.005% and about0.05%.

If it is desired, the fuel oil compositions of this invention cancontain other additives for the purpose of achieving other results.Thus, for example, there can be present foam inhibitors, anti-rustagents, and ignition and burning quality improving agents. Examples ofsuch additives are silicones, dinitro-propane, amyl nitrate, metalsulfonates and the like.

Although the present invention has been described in conjunction withpreferred embodiments, it is to be understood that modifications andvariations may be resorted to, without departing from the spirit andscope of this invention. Such variations and modifications areconsidered to be within the scope and purview of the appended claims.

I claim:

1. A distillate fuel oil containing a small amount, sufiicient toimprove the stability thereof, of a fuel-oilsoluble reaction productobtained by: reacting, at a temperature between about 50 C. and about250 C. in the presence of a catalyst selected from the group of acid andbasic catalysts, at least one molar proportion of formaldehyde with onemolar proportion of a paraflin wax-substituted hydroxyaromatic compoundrepresented by the general formula wherein R is a parafiin wax group, nand p are each small whole numbers from 1 to 3, and A is an aromaticgroup selected from the group consisting of phenyl and naphthyl, wherebyan intermediate reaction product is obtained; and reacting at atemperature between about 20 C. and about 250 C. in the presence of abasic catalyst, one molar proportion of said intermediate reactionproduct with between one and about 20 molar proportions of an alkyleneoxide.

2. A distillate fuel oil defined by claim 1 wherein the saidfuel-oil-soluble reaction product is present in an amount from about0.01 to about 0.05 percent by weight of the fuel oil.

3. A distillate fuel oil defined by claim 1 wherein th alkylene oxide isethylene oxide.

4. A distillate fuel oil defined by claim 1 wherein thealkyl-substituted hydroxyaromatic compound is a wax phenol.

5. A distillate fuel oil containing a small amount, sufficient toimprove the stability thereof, of a fuel-oilsoluble reaction productobtained by: reacting, at about 200 C. in the presence of sodiumhydroxide, one molar proportion of a parafiin-wax-substituted phenolwith one molar proportion of formaldehyde, whereby an intermediateproduct is obtained; and reacting, at about 200 C. in the presence ofsodium hydroxide, said intermediate product with about four molarproportions of ethylene oxide, whereby said fuel-oil-soluble reactionproduct is obtained.

References Cited in the file of this patent UNITED STATES PATENTS2,197,835 Reiff Apr. 23, 1940 2,454,541 Bock et al. Nov. 23, 19482,591,651 Young Apr. 1, 1952 2,692,859 Talley et a1. Oct. 26, 19542,734,032 Coppock Feb. 7, 1956 2,772,238 Lowe Nov. 27, 1956 2,786,745Stayner et a1 Mar. 26, 1957 OTHER REFERENCES Soap and SanitaryChemicals, August 1949, page 39.

Antarox," Aromatic Polyglycol Ether, Antara Products, General Aniline &Film Corp., March 3, 1950, pp. 1-6.

1. A DISTILLATE FUEL OIL CONTAINING A SMALL AMOUNT, SUFFICIENT TOIMPROVE THE STABILITY THEREOF, OF A FUEL-OILSOLUBLE REACTION PRODUCTOBTAINED BY: REACTING, AT A TEMPERATURE BETWEEN ABOUT 50*C. AND ABOUT250*C. IN THE PRESENCE OF A CATALYST SELECTED FROM THE GROUP OF ACID ANDBASIC CATALYSTS, AT LEAST ONE MOLAR PROPORTION OF FORMALDEHYDE WITH ONEMOLAR PROPORTION OF A PARAFFIN WAX-SUBSTITUTED HYDROXYAROMATIC COMPOUNDREPRESENTED BY THE GENERAL FORMULA